Paintings of Peruvian or Bolivian landscapes

Description

A set of 4 paintings that were given to me by an art collector just before she died. She said they are quite valuable but I dont know. The price is for all 4.
They seem to be of what I would guess is Lake Titicaca in Bolivia but that id jsut a guess. I'd also guess that they ar oil or acrylic rather than watercolor, but again thats just a guess. There is one small dimple in one painting that doesnt show up un less youre really looking for it and not on the photo at all.
there is no artist signature. If you know anything about them Id be greatful for any info. Disregard shipping info, shipping in the CONUS will be .00, outside the US will be actual.